COS-B

ESA (European Space Agency) mission that, together
with NASA's SAS-2, provided the first detailed
views of the Universe in gamma rays.
COS-B carried a single large experiment, the Gamma-Ray Telescope, which
was the responsibility of a group of European research laboratories know
as the Caravane Collaboration. Although originally projected to last two
years, the spacecraft operated successfully for more than six, providing
the first complete map of the Galaxy in the
2 keV-5 GeV energy range and identifying about 25 discrete sources.